Various synthetic roof and wall coverings are known today, such as those formed of elongated molded thermoplastic wall panels that are nailed or screwed to a wall or roof support surface in horizontal courses or rows in partially overlapping relation to each other so as to provide a substantially water resistant, protective layer over the support surface. Such panels, which usually are identically molded, commonly are formed with one or more rows of simulated building elements, such as shake shingles. Since the panels are identically molded, a panel-to-panel identity can be easily noticed if the panels are not carefully installed. Installation problems particularly occur when installing such synthetic wall and roof coverings about corners of the roof or sidewalls.
Typically, corner moldings are used to join the wall panels at corners of the roof or wall surfaces. In some prior corner moldings, the wall panels must be positioned into abutting relation with a pre-mounted corner molding prior to installation of the wall panel. Such mounting requires precise cutting of the ends of the panels to ensure good installation, which can substantially increase the time and cost of installation. In other known corner moldings in which an end of the wall panel is positionable into a side cavity of the corner molding, unsightly gaps can occur between the corner molding and wall panel by virtue of excessive tolerances. Such gaps also can entrap water and dirt. Moreover, since such corner moldings usually are molded for mounting on wall surfaces that define right angle corners, standard 90° corner moldings typically are not adaptable for use on corner wall surfaces angled substantially greater than 90°, such as corners of bay windows which commonly are angled at 120°.